Process of treating ores.



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Alli) FREDERICK W. HURTON, 035' WASHINGTON, DISTRICT F WELUMHIA.

To all whom it may concern: Be it known that we, iii-{MOLD Eon in VCLEAVES' and Fnnnnnlcn W. l lon'ron, citizone of the United. States, endlresidents of Washington, in the District of Columbia, have invented certain: new and. useful 1l11- provements in Processes of Treating Ores, of which the following is aspeciiication.

This 7 invention reletesltn a process of treating ores and compounds containing one er -more ofcthe metals copper, lead and zinc; and comprises subjecting such ores and cornpounds,- while 1 maintained "at a high temperature under non-oxidizing conditions, to the action 1 of a geseons reagent such as hydrogen fillifjllld;

Qn objector the present invention is the 1 rapid and'wificient treatment of ores and compounds of the above mentioned metals to producechlorids of said metals, tor the purpose-of facilitating their separation from each other'and "from otherundesireble metals andn'ne tslloids. The process is especially valuable rel.- the reason that it is'applicable to, low grade'oresnnd low grade concentra time products as well as to the higher grade meteriel.

se retion by mechanical methods exceed The trequent occurrenceof ores containing'jlarge proportions of lead and zinc min-' inglydilficnlnhas raised a problem of great importance. As is well li'nown, the exteneive deposits of, such ores at Broken Hill (N. S. W.), containing intimate mixtures of gal ena and zinc blends, have heretofore been worked With-oily degree of success only by supplementin' .the ordinary methods of dressing; by otation processes. vll. similar condition exists in the lleadville district .(Colozado) Where special methods of treatment are necessary to treethe lead ores from objectionable proportions oi zinc, end the zinc ores from objectionable proportions of lead.

The presence oi substantial proportions of zinc in a, lead ore is the cause of serious dificulties in the lead blast furnace. If zinc is present as the oxid, it enters the slag; if it is to be properly carried oli the slag must be very fusible. end the furnace must he run at a low temperature so as not to reduce the end to metal. When the zinc is m the form ct sulfide, as is otten the case,

- i nreocnss-or rnnntrrne ones" enecificetion of Ztettcrs letcnt. Patented Tuned, 1918,; Application filed March 14;, 1917. Elerial No. 154,?59. l

the blende enters both slag and matte}f.,'ren-;

their-separation, as Well as carrying other dering them less fusible and obstructing metal snlfids into the slag. When zinc oxid 1 i is reduced to metal in the lower part of the furnace, it becomes volatilized, and the ascending vapor carries with it lead and silver which cannot be conveniently recovered;

higher up the metal becomes oxidized and of the furnace.

roasting there is either a diflicu'ltly decom-f possible lead sulfate formed, or, with sufli, g.

cient silica, a lead silicate which is very fusible and tends'to envelop particles f blendc and to prevent their desulfurization.

There is also a large loss of'lead due to volatilization. Lead present during the zinc I cate Which acts corrosively on the .retortsreduction and distillation. terms lead sili and tends to hinder the reduction by en-"1 zinc, the latter being thereby contaminated. The new process consists cssentlally in veloping particles of zinc oxid; Part of the lead is also reduced and volatilized with tlie passing a current of hydrogen chloi'id in? contact with an ore or compound contaming I one or more of the metals, copper, lead, and.

zinc, associated with other metals or metalloids While maintaining the material at 'a temperature (0. 9'. 800410090.) at which a chlorid or chloride of one or more of' the metalsds formed and volatilized and rel-l moved by the current of gas. The volati-.

lined chlorids may be separated from the hydrogen chlorid by passing the gas through a condenser or into Water. When a mixture of metal chlorid is thus obtained they may be readily separated by fractional distilla- 'tion or by precipitation methods.

The following: examples illustrate the process in greater detail:

' Example ll: An ore containing an intimate mixture of. lead and zinc sulfid such as is common in the Lfldfinfi district (GoL) is finely ground andplaoed in a thin layer in o furnace; dry hydrogen chlorid is passed over the material, heated to 960-1000 (3., and the resnlting as mixture is led through a condenser-or led into Water or into a hydrochloric acid solution to separate outthe rolatilized chloride. tti'fter a short time the lead and zinc sulfids are completely decomposed and volatilized, the products of the reaction being lead chlorid, zinc chlorid and hydrogen sulfid.

Example II: Willemite (Zn SiO is finely ground and subjected at a high ternperature to the action of hydrogen chlorid, as in' Example ll. The mineral is readily decomposed, the zinc chlorid formed being volatilized and recovered by passing the gas into water. The residue remaining in the furnace consists essentially of silica.

Many other ores and minerals containing lead and zinc are quickly decomposed when treated at high temperatures with hydrogen chlorid. Thus franklinite, (Fe,Zn,Mn)O (Fe,Mn) O is almost completely decomposed and v-olatilized. Cerrussite, PbCO is readily acted on, lead chlorid being volatilized. As other instances of minerals which may be successfully treated there may be .mentioned zincite, (Zn,Mn O, smithsonite,

ZnCO,, and c'alamine, Zn( H) SiO ,The process as applied to ores and miner-- al's containing copper may be illustrated as follows:

Example III: Chrysocolla, CuSiO .2I-I,O, is finely ground and, while heated to about 1000 C., is treated with hydrogen chlorid. In a short time the mineral is decomposed,

the copper chlorid which is formed being volatilized, leaving practically pure silica in the furnace.

Example IV: Ohalcopyrite, CuFeS. is heated to 1000-1100 C. and a stream of dry hydrogen chlorid is passed over the heated material. are quickly formed and svolatilized along with hydrogen su1fid. A small amount of silica, which was present in the mineral, remains in the furnace.

Ores containingsuch minerals as chalcocite 011 s), cuprite (Cu O), malachite (CuCO .Ou (OH) azurite (2C11CO .Cu (OH) bornite (Ou FeS tenorite (CuO) tetrahedrite (4Cu,S.Sb S,), etc., are readily acted on, the chlorids of the metals being formed and volatilized with great celerity, leaving. a residue of silica which innnany cases seems to be practically pure SiO In order ti prevent unnecessary loss of hydrogen chlorid, and reoxidation of the metals in the material treated, it is desirable tocarry out the process with the exclusion undesirable substances,

The chlorids of iron and copper of air. The hydrogen chlorid should be dry for the same reason.

Hydrogen halids other than hydrogen chlorid may be used to form metal halids, but they are as a rule more expensive than hydrogen chlorid and offer no special advantages.

We claim:

1. The process of treating ores or compounds which contain one or more of the metals copper, lead, and zinc, associated with which comprises treating such ores or compounds with a gas eous reagent capable of reacting with said metals under non-oxidizing conditions to form volatile metal compounds, while maintaining such ores or compounds at a temperature at which one or more of the metal compounds thus formed will be volatilized.

2. The process of treating ores or compounds which contain one or more of the metals lead and zinc, which comprises treating such ores or compounds with a gas containing hydrogen chlorid, while maintaining the ores or compounds at a temperature at which one or more metal chlorids will be formed and volatilized.

3. The process of treating ores or compounds which contain one or more of the metals lead and zinc, which comprises treating such ores or compounds with a gas containing hydrogen chlorid, while maintaining the ores or compounds at a temperature of from 800 to 1100 C.

4-. The process of treating ores containing lead and zinc sulfids which comprises pass ing hydrogen chlorid in contact with the ore, while maintaining the latter at a temperature at which lead and zinc chlorids and hydrogen sulfid will be formed and at least one of said substances volatilized.

5. The process of treating material containing lead and zinc sulfids which comprises HAROLD EDWIN CLEAVLES. FREDERICK W. HORTON. 

